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A reference to the populated Hashtable object referred to by piano is returned when the for loop terminates at the bottom of Listing 18 .

Listing 18 also signals the end of the getPiano method and the end of the class named PlayerPiano01 . However, we aren't finished yet. We need to go back and examine the code in the method named makeMusic that we put on the back burner a little earlier.

Beginning of the method named makeMusic

The method named makeMusic begins in Listing 19 . This method transforms the notes for a clef into an array of amplitude values. This method doesn't know the difference between a treble clef and a bass clef.It is called once to transform the treble clef at the bottom of Listing 12 . It is called again to transform the bass clef in Listing 13 if the user provides a text file containing bass clef data.

Listing 19 . Beginning of the method named makeMusic.
void makeMusic(ArrayList clef,int beatsPerSec){ double gain = 4000.0;//Set the output volume to a reasonable level.//Get a hashtable that maps note names into note frequencies from A2 // through A7. Note that the name "X" is used to indicate a period of// silence or a rest, so it is appended onto the end of the hashtable with // a frequency of 0.0.//Frequency values can be checked against // http://www.phy.mtu.edu/~suits/notefreqs.html.Hashtable piano = getPiano(); piano.put("X",0.0);//Miscellaneous variables double freq = 0;int beats = 0; double scaleFactor = 0;

Nothing in Listing 19 should require an explanation beyond the embedded comments.

Process each array containing duration and note names in the ArrayList object

Listing 20 shows the beginning of a while loop that uses an iterator to process each array containing duration and note names in the ArrayList object

Listing 20 . Process each array containing duration and note names in the ArrayList object.
Iterator iter = clef.iterator(); while(iter.hasNext()){//Get the next array containing duration and note names String[]array = (String[])iter.next();//Get the duration of the note in beats beats = Integer.parseInt(array[0]);

The code in Listing 20 accesses the next array and then extracts the duration (in beats) from the array and stores it in the variable named beats .

Process each sample

Listing 21 shows the beginning of a for loop that is used to process each sample that makes up this note. The output sampling rate is constant. Therefore,notes with a short duration comprise fewer samples than notes with a long duration.

Listing 21 . Process each sample.
for(int cnt = 0; cnt<beats*audioParams.sampleRate/beatsPerSec; cnt++){ //Compute the time for this iteration to use when evaluating the// cosine function. double time = cnt/audioParams.sampleRate;double sum = 0;//sum of values for this iteration

Process each piano key that is pressed

Recall that a human piano player can press several keys simultaneous, as in (9,A3,C4,E4) at the end of Listing 30 . In this case, the piano player would press threekeys simultaneously on the piano keyboard and hold them down for nine beats.

Questions & Answers

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The denominator of a certain fraction is 9 more than the numerator. If 6 is added to both terms of the fraction, the value of the fraction becomes 2/3. Find the original fraction. 2. The sum of the least and greatest of 3 consecutive integers is 60. What are the valu
1. x + 6 2 -------------- = _ x + 9 + 6 3 x + 6 3 ----------- x -- (cross multiply) x + 15 2 3(x + 6) = 2(x + 15) 3x + 18 = 2x + 30 (-2x from both) x + 18 = 30 (-18 from both) x = 12 Test: 12 + 6 18 2 -------------- = --- = --- 12 + 9 + 6 27 3
2. (x) + (x + 2) = 60 2x + 2 = 60 2x = 58 x = 29 29, 30, & 31
on number 2 question How did you got 2x +2
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Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has 1 more than 3 times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is 113?
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Mark = x,. Don = 3x + 1 x + 3x + 1 = 113 4x = 112, x = 28 Mark = 28, Don = 85, 28 + 85 = 113
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Solve for the first variable in one of the equations, then substitute the result into the other equation. Point For: (6111,4111,−411)(6111,4111,-411) Equation Form: x=6111,y=4111,z=−411x=6111,y=4111,z=-411
x=61/11 y=41/11 z=−4/11 x=61/11 y=41/11 z=-4/11
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Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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Source:  OpenStax, Accessible objected-oriented programming concepts for blind students using java. OpenStax CNX. Sep 01, 2014 Download for free at https://legacy.cnx.org/content/col11349/1.17
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